A scanning probe microscope (SPM) has been known as a measuring technique of a micro stereoscopic shape. In this technique, an atomic force microscope (AFM) is an observing technique of scanning a sample surface while keeping a contact force to a very small value by controlling an acuate probe, and has been widely used as a technique which can measure an atomic order micro stereoscopic shape. However, the atomic force microscope can not measure an optical property such as a reflectivity distribution and a refractive index distribution of a sample surface.
On the other hand, in an extra fine semiconductor device after 45 nm node, an application of a strain silicone is scheduled for speeding up, and it is absolutely necessary for managing a yield ratio to measure a stress distribution in a micro region. Further, in order to achieve a further refinement, it is demanded to carefully manage a distribution condition of an impurity atom by a nanometer order resolution. A physical property information such as a stress distribution, an impurity distribution and the like can not be measured by the atomic force microscope or a CD-SEM (a critical dimension SEM) used for managing a dimension. An optical method such as a Raman spectrometer measuring method and the like has been under review, however, a spatial resolution comes short in a general Raman spectroscopic micrometer.
Further, in order to specify a generation factor of a foreign particle and a defect detected by a foreign particle inspection and a defect inspection, a classifying work of the foreign particle and the defect is carried out by an electron microscope called as a review SEM, however, since it is a method depending only on a shape and a surface profile information, there is a limit in a classifying performance. In this case, it is possible to expect an improvement of the classifying performance by adding the optical information, however, the spatial resolution still comes short in the general optical microscope and laser scanning microscope.
As a means which solves these problems and measures the optical characteristics and the physical information of the sample surface at a high resolution, a scanning near-field optical microscope (SNOM) has been known. This microscope is structured such as to measure the optical characteristics such as the reflectivity distribution and the refractive index distribution of the sample surface at a resolution of some tens nm which is the same magnitude as an opening beyond a light diffraction limit, by scanning a near field light leaking from a micro aperture of some tens nm while keeping a gap between the aperture and the sample at the same some tens nm (an aperture probe), as disclosed in non-patent document 1. As a similar method, non-patent document 2 discloses a method of irradiating a light onto a metal probe from an external portion so as to scan the near field light having the magnitude of some tens nm which is scattered by a micro bottom of the probe (a scattering probe).
Further, non-patent document 3 describes a matter that a surface plasmon excited to a gold nano particle 2a by a micro spot light propagates one after another between the gold nano particles.
Further, patent document 1 discloses a method of forming a micro spot light by forming a micro spherical lens in a leading end of a fiber.    Patent Document 1: JP-A-2006-515682    Non-patent Document 1: Japanese Journal of Applied Physics, Vol. 31, pp. L1302-L1304 (1992)    Non-patent Document 2: Optics Letters, Vol. 19, pp. 159-161 (1994)    Non-patent Document 3: Spectroscopic Research, Vol. 54, Number 4, pp. 225-237 (2005)